There are many prior art pieces of equipment for detaching or bursting continuous business forms in general (such as shown in U.S. Pat. No. 30,398 and U.S. Pat. No. 3,741,451), as well as apparatus for bursting conventional labels with release sheets from a fan fold stack, such as shown in U.S. Pat. Nos. 5,100,040 and 4,375,189. However such equipment is not appropriate for detaching linerless labels. In co-pending application Ser. No. 07/982,699 filed Nov. 30, 1992, now U.S. Pat. No. 5,417,783, linerless label dispenser is provided which is semi-automatic. As each label is dispensed an operator tears the label off using a tear bar. As the operator is applying the dispensed label, the dispenser automatically advances the next label. While this arrangement is useful, it is significant that a sense mark (registration mark) must typically be printed on each label, and the machine is more expensive than desired.
According to the present invention a method and apparatus are provided for the automatic, or optionally semi-automatic, dispensing of linerless labels, which automatically detach or burst the labels using a basically conventional and proven bursting technique, but specifically adapting the technique and the apparatus so that it is capable of functioning with linerless labels. The detacher/dispenser according to the present invention requires no sense mark, the unit may be produced very cost effectively, an operator is not required to manually tear off a label, registration may be achieved quickly and mechanically yet set up by the operator, and a wide variety of linerless labels can be utilized, including those having repositional adhesive or permanent adhesive.
According to one aspect of the present invention, a method of dispensing linerless labels disposed in a rolled web having transverse perforations at spaced locations along the length thereof, and having a first surface (e.g. coated with a release material such as silicone) that will not readily adhere to adhesive (either repositional or permanent) on a second surface of the label web, arid a tree end of the rolled web. The method is practiced using a pair of slow speed rolls forming a nip between them, a pair of high speed rolls forming a nip between them, and a breaker blade located between the nips. The method comprises the steps of: (a) Pulling the free end of the rolled web with the slow speed rolls, in a first direction. (b) Feeding the free end of the web beneath the breaker blade, with the second surface facing away from the blade, as the web moves in the first direction. And, (c) grasping the free end with the high speed rolls and pulling the web so that the first surface of the web comes into contact with the breaker blade approximately at a perforation thereof, so that the web detaches at the perforation.
The method also preferably comprises the step (d) of sensing the detached label downstream of the high speed roll in the first direction, and stopping the low speed rolls in response to the sensing. Step (d) may be practiced by optical sensing. The method may also include restarting the high and low speed rolls when a label is removed from the high speed rolls, or requiring manual restart of the low and high speed rolls after step (d).
Step (b) may be practiced by using one or more conveyor belts having non-stick upper surfaces for engaging the second surface of the labels and transporting them in a first direction. The method may also comprise the step of carrying the detached labels away with the conveyor belts.
According to another aspect of the present invention a detacher for continuous business forms is provided, particularly for linerless labels. The detacher comprises the following elements: First and second low speed rolls forming a nip between them. First and second high speed rolls defining a nip between them. The first and second low and high speed rolls rotatable about parallel axes with an imaginary plane extending between the nips of the low and high speed rolls. A breaker blade mounted between the low and high speed rolls, on the first roll side of the imaginary plane extending between the nips, the breaker blade having a tip portion extending to the opposite side of the plane. A let-off roll on the opposite side of the low speed rolls from the breaker blade, and defining a let-off axis parallel to the low and high speed rolls. And, a sensor on the opposite side of the high speed rolls from the breaker blade, for sensing a label passing through the nip of the high speed rolls.
At least the second roll of both the low speed and high speed rolls has a non-stick surface, and the breaker blade has a tip portion which engages the business form which has a non-stick surface. A sensor is typically provided on the opposite side of the high speed rolls from the breaker blade, and a one way clutch is provided for the high speed rolls to allow detached labels to be pulled through them when the high speed rolls have stopped. Typically both the first and second rollers of the low and high speed rolls have non-stick surfaces, for example one surface may be plasma coated, and the other may be urethane or impregnated with silicone oil. One or more transport belts having non-stick surfaces also may be provided between the high and low speed rolls for feeding linerless labels from the low speed rolls to the high speed rolls, and the same belts can be used to carry the detached labels away.
Various control means may also be provided comprising control means for controlling the operation of the low and high speed surfaces, the control means including means for automatically controlling the low speed rolls in response to the sensor, and means for manually controlling the low speed rolls once stopped by the sensor. The control means preferably includes a multi-position electrical switch having an automatic position to which the switch may be turned and maintained in that position, and a manual position to which the switch may be turned is automatically spring biased away from that position.
It is the primary object of the present invention to provide a method and apparatus for the cost effective simple, easy, and reliable dispensing/detaching of linerless labels from a roll. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.